I don't think I'll ever understand the sense of entitlement people who advocate this idea of 'copyleft license or else' seem to have.

There's nothing bad about Apple not using a copyleft license. I'm glad we live in a world where they can pick any license they want. Apple could have kept Swift closed source if they wanted, and I would have been okay with that - while I might have liked for them to make it open source, it's completely up to them what they want to do with it.